1. Field of the Invention
The present invention relates to a distribution structure, a vertical shaft impact crusher having the distribution structure and a method of fabricating the distribution structure. More particularly, the present invention relates to a distribution structure for horizontally distributing an aggregate that is supplied in a vertical shaft impact crusher for pulverizing the aggregate into gravels and sands, a vertical shaft impact crusher having the distribution structure and a method of fabricating the distribution structure.
2. Description of the Related Art
A natural aggregate is pulverized using a crusher in accordance with various applications. The crusher includes a vertical shaft impact crusher. The vertical shaft impact crusher pulverizes the natural aggregate by crushing a highly accelerated aggregate against a crushing face. The vertical shaft impact crusher may be classified into an anvil type crusher and a rock-on-rock type crusher.
FIG. 1 is a cross sectional view illustrating a conventional anvil type impact crusher that is disclosed in U.S. Pat. No. 5,135,177.
Referring to FIG. 1, a conventional impact crusher includes a crushing chamber 1 and a feeding hopper 2 disposed over the crushing chamber 1. A rotor 3 for providing a centrifugal force to an aggregate is positioned in the crushing chamber 1. The aggregate is loaded into the rotor 3 through the feeding hopper 2. A conoid distribution structure 5 is arranged at a central portion of a bottom face of the rotor 3. The distribution structure 5 distributes the aggregate, which is vertically loaded into the rotor 3, in a horizontal direction. The distribution structure 5 is fixed to a vertical shaft for rotating the rotor 3 so that the distribution structure 5 is rotated together with the rotor 3. An anvil 4 is mounted on an inner wall of the crushing chamber 1. The aggregate is crushed against the anvil 4.
The aggregate loaded into the rotor 3 is crushed against the distribution structure 5 and is then moved in the horizontal direction. Thus, the distribution structure 5 together rotated with the rotor 3 violently chafes against the aggregate so that the distribution structure 5 is readily worn. As a result, the distribution structure 5 is periodically replaced with new one.
Meanwhile, the conventional distribution structure 5 includes high chromium steel. The distribution structure 5 including high chromium steel may have life span of about 150 hours. Thus, the conventional vertical shaft impact crusher is suspended at an interval of about 150 hours to replace the distribution structure 5 with new one. This causes reduction of an operational efficiency of the conventional vertical shaft impact crusher.
To overcome the above-mentioned problem, ceramic or tungsten carbide having a wear resistance higher than that of high chromium steel may be used for a material of the conventional distribution structure. However, although the conventional distribution structure including ceramic or tungsten carbide has life span of about 10 times to about 15 times longer than that of the distribution structure including high chromium steel, ceramic or tungsten carbide is more expensive than high chromium steel so that cost for fabricating the distribution structure including ceramic or tungsten carbide is about 30 times to about 40 times more expensive than that for fabricating the distribution structure including high chromium steel. As a result, ceramic or tungsten carbide may not be realistically used for a material of the distribution structure in the light of economy.